In German patent 3,541,888 of W. Friedrich and German utility model 8,104,864 position indicators are shown which indicate the angular position of a shaft that can turn through more than one revolution between end positions. This is the case in a step switch for a transformer that is used to change the voltage output and that is normally switched when the power is off.
As a rule such a positioner is operated manually and in a multi-phase system the shaft is connected by gearing to the shafts of switches for the various phases. The operator fits a crank or wrench to the end of the adjustment shaft and rotates it until the desired position number is visible in a window in the positioner housing. The normal angular displacement from position to position is equal to (360-360/n).degree. where n is the number of contacts and therefore also the number of positions. This is necessary because the switch element is not only rotated but also moved radially by an eccentric as it rotates out of engagement with the contacts.
In the system of German patent 3,541,888 a crank-carrying adjustment shaft parallel to and spaced from the switch shaft is connected to this switch shaft by stepdown gearing. The adjustment shaft carries a disk bearing angularly spaced indicia and the switch shaft carries a disk having an aperture that can be aligned with the indicia of the switch shaft. Such an arrangement is fairly complex and bulky.
The system of German Utility Model 8,104,864 has a disk bearing the indicia and carried on a shaft coupled through gearing to the switch shaft, with the indicia laid out in a multiturn spiral. A window formed in a radially displaceable element can be aligned with the various turns of the spiral and is radially displaced by a cam coupled to the indicia disk. Once again this system is fairly bulky.